Visual and automatic classification of the cyclic alternating pattern in electroencephalography during sleep

Cyclic alternating pattern (CAP) is a neurophysiological pattern that can be visually scored by international criteria. The aim of this study was to verify the feasibility of visual CAP scoring using only one channel of sleep electroencephalogram (EEG) to evaluate the inter-scorer agreement in a variety of recordings, and to compare agreement between visual scoring and automatic scoring systems. Sixteen hours of single-channel European data format recordings from four different sleep laboratories with either C4-A1 or C3-A2 channels and with different sampling frequencies were used in this study. Seven independent scorers applied visual scoring according to international criteria. Two automatic blind scorings were also evaluated. Event-based inter-scorer agreement analysis was performed. The pairwise inter-scorer agreement (PWISA) was between 55.5 and 84.3%. The average PWISA was above 60% for all scorers and the global average was 69.9%. Automatic scoring systems showed similar results to those of visual scoring. The study showed that CAP could be scored using only one EEG channel. Therefore, CAP scoring might also be integrated in sleep scoring features and automatic scoring systems having similar performances to visual sleep scoring systems.

Diagnostic and Clinical Differences in Obstructive Sleep Apnea Syndrome and Upper Airway Resistance Syndrome / 수면정신생리

It has been controversial whether upper airway resistance syndrome (UARS) is a distinct syndrome or not since it was reported in 1993. The International Classification of Sleep Disorders classified UARS under obstructive sleep apnea syndrome (OSAS) in 2005. UARS can be diagnosed when the apnea-hypopnea index (AHI) is fewer than 5 events per hour, the simultaneously calculated respiratory disturbance index (RDI) is more than 5 events per hour due to abnormal non-apneic non-hypopneic respiratory events accompanying respiratory effort related arousals (RERAs), and oxygen saturation is greater than 92% at termination of an abnormal breathing event. Although esophageal pressure measurement remains the gold standard for detecting subtle breathing abnormality other than hypopnea and apnea, nasal pressure transducer has been most commonly used. RERAs include phase A2 of cyclical alternating patterns (CAPs) associated with EEG changes. Symptoms of OSAS can overlap with UARS, but chronic insomnia tends to be more common in UARS than in OSAS and clinical symptoms similar with functional somatic syndrome are also more common in UARS. In this journal, diagnostic and clinical differences between UARS and OSAS are reviewed.

Avaliação da arquitetura do sono em crianças com epilepsia refratária / Evaluation of sleep architecture in children with refractory epilepsy

INTRODUÇÃO: Há um interesse crescente nas relações entre sono e epilepsia incentivado pela compreensão de que existem interações potencialmente relevantes nas duas direções. Embora o papel do sono na hipersincronização e a crescente preocupação na geração de crises sejam bem conhecidos, o grau no qual o sono pode facilitar ou induzir a um fenômeno epileptogênico, nas epilepsias lesionais, permanece indefinido. As epilepsias lesionais parecem apresentar um mecanismo particular de epileptogenicidade e o esclarecimento do papel da macro e microarquitetura do sono pode auxiliar na antecipação e monitorização de fenômenos epilépticos relacionados ao sono, conforme a etiologia da epilepsia. OBJETIVO: revisar e discutir as relações entre sono e epilepsia na infância e adolescência relacionando as alterações estruturais do sono à etiologia da epilepsia. MÉTODOS: revi-são bibliográfica utilizando o banco de dados Medline, abrangendo os estudos publicados nos últimos quinze anos, com as palavras-chave (unitermos) sono e epilepsia. CONCLUSÕES: epilepsia refratária durante a infância parece influenciar a organização do sono principalmente naqueles pacientes com etiologia lesional. A definição do tipo de epilepsia pode ser importante na antecipação dos distúrbios de sono nesta população.

ABSTRACT INTRODUCTION: There has been a growing interest in the relations between sleep and epilepsy, kindled by the realization that there are many potentially relevant two-way interactions. Even though the hyper-synchronizing role of sleep and its attending increase in the probability of seizure generation are well known, the degree to which sleep may facilitate or induce epileptogenic phenomena in lesional epilepsies remains unclear. The lesional epilepsies seems to have intrinsic epileptogenic properties and the knowledge about sleep macro and microarchiteture could help clinician to anticipate and monitor sleep-related epileptic phenomena according to the etiology of the epilepsy OBJECTIVE: Discuss the relationship between sleep and epilepsy in childhood and adolescence. METHODS: Literature review in journals indexed through Medline, from the last 15 years. CONCLUSION: Refractory epilepsy during childhood influences sleep organization mainly in patients with lesional etiology. The definition of the type of epilepsy is important to anticipate sleep disorders in this population.

Cyclic alternating pattern in normal children aged 12 to 24 months / Padrão alternante cíclico em crianças normais de 12 a 24 meses

OBJECTIVE: The aim of this study is to complement existing data on the expression and characteristics of cyclic alternating pattern (CAP) in children, specifically in the 12 to 24 month age bracket. METHOD: Descriptive study. Settings: a university pediatric sleep laboratory. Participants: Twelve normal and healthy subjects (6 girls and 6 boys, mean age 18.9±4.72 months; range 12-24 months underwent a standard polysomnography night recording in our pediatric sleep laboratory. Sleep stages and CAP were analyzed according to standard international rules. RESULTS: CAP rate found in children of 12 to 24 months of age was (25.78±10.18 percent) and it is characterized by a linear increase of 2 percent per month, from 12 percent at 12 months reaching 35 percent at 24 months. With coefficient of determination R² of 0.91. The duration of A phases was 6.93±1.06 seconds, and B phases was found to last 21.44±2.31 seconds. The number of CAP cycles was 173.25±73.85 with an average index per hour of 33.55±14.61. The number of CAP sequences reached 25.25±9.55 per recording. CAP rate for the different type of A phases are (21.83±9.68 percent), for A1, (2.43±2.30 percent) for A3 and (1.67±1.11 percent) for A2. CONCLUSION: Our study provides normative data on CAP in a group of young children (12 to 24 months). The most salient result of this study is the strong correlation of CAP rate of 2 percent per month in this age group.

OBJETIVO: O objetivo deste estudo é complementar os dados normativos sobre a expressão e as características do padrão alternante cíclico (CAP) em crianças, especificamente na faixa etária de 12 para 24 meses. MÉTODO: Estudo descritivo. Participantes: Doze indivíduos normais e saudáveis (6 meninas e 6 meninos, entre 12-24 meses de idade (média de 18,9±4,72 meses), foram submetidos a uma noite de gravação de polissonografia em nosso laboratório de sono pediátrico. As fases do sono e CAP foram analisados de acordo com padrão e normas internacionais. RESULTADOS: A taxa máxima encontrada em crianças de 12 a 24 meses de idade foi de (25,78 por cento±10,18) e é caracterizada por um aumento linear de 2 por cento ao mês, a partir de 12 por cento em 12 meses atingindo 35 por cento em 24 meses de idade. A duração da fase A foi de 6,93±1,06 segundos, e nas fases B foi encontrado a média de 21,44±2,31 segundos. O número de ciclos CAP foi 173,25±73,85, com um índice médio por hora de 33,55±14,61. O número de sequências CAP chegou a 25,25±9,55 por registro.Os índices dos subtipos de fases A foram (21,83 por cento±9,68), para a A1, (2,43 por cento±2,30) para a A3 e (1,67 por cento±1,11) para A2. CONCLUSÃO: Nosso estudo fornece dados normativos sobre CAP em um grupo de crianças (12 a 24 meses de idade). O resultado mais saliente deste estudo é a forte correlação entre taxa do CAP e idade, mostrando que a cada mês ocorreu o aumento de 2 por cento.

Cyclic Alternating Pattern in Sleep (review) / 中国康复理论与实践

@#Cyclic alternating pattern (CAP) during sleep is a kind of cyclic oscillation of EEG pattern in non-rapid eye movement sleep(NREM sleep), which reflects microstructure of sleep. It has been identified that CAP plays an important role in keeping the integrity of sleep. The purpose of the interview is to introduce the recording, identification, physiological meaning and clinic implication of CAP.

Cyclic Alternating Pattern: Implications for Insomnia / 수면정신생리

The cyclic alternating pattern (CAP) is a periodic EEG activity in NREM sleep, characterized by sequences of transient electrocortical events that are distinct from background EEG activities. A CAP cycle consists of two periodic EEG features, phase A and subsequent phase B whose durations are 2-60 s. At least two consecutive CAP cycles are required to define a CAP sequence. The CAP phase A is a phasic EEG event, such as delta bursts, vertex sharp transients, K-complex sequences, polyphasic bursts, K-alpha, intermittent alpha, and arousals. Phase B is repetitive periods of background EEG activity. The absence of CAP more than 60 seconds or an isolated phase A is classified as non-CAP. Phase A activities can be classified into three subtypes (A1, A2, and A3), based on the amounts of high-voltage slow waves (EEG synchrony) and low-amplitude fast rhythms (EEG desynchrony). CAP rate, the percentage of CAP durations in NREM sleep is considered to be a physiologic marker of the NREM sleep instability. In insomnia, the frequent discrepancy between self-reports and polysomnographic findings could be attributed to subtle abnormalities in the sleep tracing, which are overlooked by the conventional scoring methods. The conventional scoring scheme has superiority in analysis of macrostructure of sleep but shows limited power in finding arousals and transient EEG events that are major component of microstructure of sleep. But, it has recently been found that a significant correlation exists between CAP rate and the subjective estimates of the sleep quality in insomniacs and sleep-improving treatments often reduce the amount of CAP. Thus, the extension of conventional sleep measures with the new CAP variables, which appear to be the more sensitive to sleep disturbance, may improve our knowledge on the diagnosis and management of insomnia.

Delta sleep instability in children with chronic arthritis

The objective of the present study was to evaluate the expression of a cyclic alternating pattern (CAP) in slow wave sleep (SWS) in children with the well-defined chronic syndrome juvenile idiopathic arthritis (JIA). Twelve patients (9-17 years of age), 7 girls, with JIA were compared to matched controls by age, pubertal stage and gender. After one night of habituation in the sleep laboratory, sleep measurements were obtained by standard polysomnography with conventional sleep scoring and additional CAP analyses. The sleep parameters of the JIA and control groups were similar for sleep efficiency (91.1 ± 6.7 vs 95.8 ± 4.0), sleep stage in minutes: stage 1 (16.8 ± 8.5 vs 17.8 ± 4.0), stage 2 (251.9 ± 41 vs 262.8 ± 38.1), stage 3 (17.0 ± 6.0 vs 15.1 ± 5.7), stage 4 (61.0 ± 21.7 vs 77.1 ± 20.4), and rapid eye movement sleep (82.0 ± 27.6 vs 99.0 ± 23.9), respectively. JIA patients presented nocturnal disrupted sleep, with an increase in short awakenings, but CAP analyses showed that sleep disruption was present even during SWS, showing an increase in the overall CAP rate (P < 0.01). Overall CAP rate during non-rapid eye movement sleep was significantly higher in pediatric patients who were in chronic pain. This is the first study of CAP in pediatric patients with chronic arthritis showing that CAP analyses can be a powerful tool for the investigation of disturbance of SWS in children, based on sleep EEG visual analysis.